Method of and apparatus for controlling electrical circuits



Feb. 7, 1939. W.E. REED 2,146,652

METBOD OF AND APPARATUS FOR CONTROLLING ELECTRICAL CIRCUITS .Fileci Oct. 21, 1933 INVENTOR 1 I! l {"1 @M Wm W Patented Feb. 7, 1939 'UNITED STATES PATENT METHOD OF AND APPARATUS FOR CON- TROLLING ELECTRICAL CIRCUITS trodes, in the making of wire mesh, and only so much of the Welding machine is shown as is required to an understanding of the invention, the complete machine being disclosed in my Patent No. 1,694,081.

Referring now to Fig. l, I show a structure wherein a circuit is established through a gasfilled electronic tube 66, with an electromagnet 81, for effecting de-energization of the circuit, to thereby control the duration of current flow at the transformer 68, and consequently to welding electrodes 69, it being understood, of course, that the electrical impulses in the tube circuit may be employed for other purposes than welding, as

'7 Claims.

The invention relates primarily to the control of electrical circuits wherein it is desired that the application of current be of extremely short duration, and whereby such applications of current may be repeated at definite or periodic times, as may be desired.

While the invention is hereinafter described more in detail as applied to the electrical welding of material in those cases where the material is of small cross section such as wires of the smaller gages, it may be employed also in the producing of various other electrical effects such as flash signalling, power flashes, vibrations, and other electrically-produced impulses of short duration.

My invention has for its object the provision of heretofore explained.

a method for effecting impulses or forces of eX- Upon closing of the switch it of AC line H, by remely short duration through the setting up of movement of the conveyor as shown in my said two forces, which produce opposite results, in patent or otherwise, a transformer l2 will be such manner that the application of the desired energized to establish flow of current through working force is of shorter duration than is posconductor "IS-l4, electrodes l5 and '16 of tube sible in those cases where a circuit-making and 56, and conductor i1, thereby effecting energizacircuit-breaking forces are established in setion of the load or transformer 53. The filament quence. i6 is permanently heated from a suitable source In many cases the duration of current flow deof current through a transformer 18, so that the 23 sired is less than the time required to initiate circuit will be instantly energized upon closing separate forces in sequence and they must thereof the switch 10. fore be initiated simultaneously and be of such Closing of the switch it energizes the electroa character that they cause a current flow folmagnet Bl, which effects closing of a switch 19. lowed by the interruption thereof after an ex- The speed of operation of the magnet is such tremely short duration of current flow. Such that current will fiow through the transformers forces may have different characteristics, and for an appreciable period of time before the they may be constant or varying forces, and one switch 79 is closed. This lag in operation can may vary in increasing strength, while the other be varied by controlling the speed of operation of is varying in decreasing strength, and vice versa, the electromagnet in any of well-known ways, and they may vary periodically so that first one for example, as stated in my Patent 1,932,119. force prevails and then the other, to produce a Upon excitation of the transformer '52, the grid flow and then an interruption, or be performed 80 of the tube is given a positive potential relative repeatedly over a desired period of time. Such to the cathode. Upon closing of the switch 19, forces may be mechanical, electrical, or magthe grid is rendered negative thereto, and cur- 40 netic, or a combination of such forces. The sirent flow through the tube is interrupted.

multaneously-initiated forces may also first make The negative potential on the grid Bil is efcurrent flow and instantaneously develop condifected because the conductor 85 of the switch is tions which will prevent the continuation of this connected to the secondary transformer winding new at a point farther from the middle and is more 40 Some of the ways by which the invention may negative than is the filament conductor l1, while be practised are shown in the accompanying conductor 82 to which the grid fit is initially condrawing, wherein Figure 1 is a partially dianected is given positive potential relative to the grammatio view showing one manner in which potential on line ll. Resistance coil 82a is for the flow of welding current may be controlled, the purpose of preventing short-circuiting of and Fig. 2 shows a modification of the structure part of the transformer through switch it. The of Fig. 1. duration of current fiow to the welding electrodes As one specific example of the manner in is therefore definitely limited, even though the which the invention may be practised, the acswitch 10 may be held closed, and each closing companying drawing illustrates a portion of a movement of the switch will result in an electrimachine for supplying current to welding eleccal impulse of limited duration to the load.

Referring now to Fig. 2, I show an arrangement somewhat similar to that above, in that the how of current is set up through a gaseous electronic tube 83, but instead of changing the grid from the positive to negative potential, I interrupt the tube circuit by a switch 84 which is operated in the same manner as the switch 19. Thus when the line switch 10 is closed, current will immediately flow through the electronic tube and the switch magnet be simultaneously energized. When the switch magnet becomes fully efiective, it will physically break the tube circuit,

There are various other ways that electronic tubes may be used in the practising of this invention. Tubes acting as time delay relays may be used for one or both of the electro-responsive devices described. There are also several ways of producing ionization and deionization of a tube and limiting the duration of current flow to the load. This duration may be measured in cycles or in fractions of one cycle.

In welding fabric current application may be controlled for asingle Weld or may be periodically applied for a fixed speed of movement of the Work-or it may be applied at a frequency proportional to and in synchronism with the speed of movement of the work.

Although I have shown specific applications, there are various other ways the method may be practised and appliedwhere single tubes act 'as rectifiers, double rectification may be used by employing two tubes.

' I claim as my invention:-

1. The method of controlling duration of current flow in the load or output circuit of a gas filled power tube, which comprises simultaneously setting up or initiating two tube-controlling electro-motive forces, applying one E. M. F. to produce ionization and current fiow through the tube, applying the other E. M, F. to produce de-ionization and cessation of current flow through the tube, and causing a time delay in the application of said other E. M. F. relative to the application of said first E. M. F. independently of the current fiow in the load circuit.

2. The method of controlling duration of current fiow in the load or output circuit of a gas filled power tube, which comprises simultaneously setting up or initiating an electric potential that produces ionization and current flow in the tube and another electric potential that destroys said ionization and current flow independently of the current flow in the load circuit, and applying said potentials in time-spaced relation.

3. The method of controlling duration of current fioW in the load or output circuit of a gas filled power tube, which comprises simultaneously setting up or initiating an electric potential that produces ionization and current fiow in the tube and another electric potential that destroys said ionization and current flow, applying said potentials in time-spaced relation, and controlling the timing period between the application of said forces, independently of-the current flow in the load circuit.

4. The method of controlling current flow in the load circuit of a gas filled power tube which comprises applying an electric potential that produces ionization and current flow through the tube, initiating simultaneously with the said potential a second electric potential to destroy said ionization, and causing the second potential to be concurrently but more slowly operative than the first-named potential, independently of the current flow in the load circuit.

5. The method of controlling current flow in the output circuit of a gas filled power tube which comprises simultaneously initiating a positive grid bias potential that produces ionization and a current flow through the tube and a second electrical potential to destroy the said ionization, applying said potentials, but causing said second potential to be applied subsequent to the application of said first potential, independently of the current fiow in the output circuit.

6. In an electrical timing system, the combination with a load circuit and an electronic tube, for controlling current flow thereto, of circuit means for connecting said tube and load circuit to a. source of electric energy, control means responsive to application of electric potential to said circuit means for setting up current flow in said tube and said load circuit, electro-responsive means in said circuit means for controlling current fiow therein, and means for simultaneously applying operating electrical energy to said circuit means and said electro-responsive means, said electro-responsive means being more slowly responsive to energization than the said control means.

7. In an electrical timing system, the combination with a load circuit and an electronic tube, for controlling current fiow thereto, of circuit means for connecting said tube and load circuit to a source of electric energy, a control electrode for said tube, means for applying positive biasing potential to said electrode to cause current flow in the tube, electro-responsive means in said circuit means, for acting upon said biasing means to discontinue said flow, and means for simultaneously applying operating electrical energyto said circuit means and said electro-responsive means, said electro-responsive means being more slowly responsive to energization than the said control means.

WILLIAM EDGAR REED. 

